Synthesis of Catechol Derived Rosamine Dyes and Their Reactivity toward Biogenic Amines

Functional organic dyes play a key role in many fields, namely in biotechnology and medical diagnosis. Herein, we report two novel 2,3- and 3,4-dihydroxyphenyl substituted rosamines (3 and 4, respectively) that were successfully synthesized through a microwave-assisted protocol. The best reaction yields were obtained for rosamine 4, which also showed the most interesting photophysical properties, specially toward biogenic amines (BAs). Several amines including n- and t-butylamine, cadaverine, and putrescine cause spectral changes of 4, in UV–Vis and fluorescence spectra, which are indicative of their potential application as an effective tool to detect amines in acetonitrile solutions. In the gas phase, the probe response is more expressive for spermine and putrescine. Additionally, we found that methanolic solutions of rosamine 4 and n-butylamine undergo a pink to yellow color change over time, which has been attributed to the formation of a new compound. The latter was isolated and identified as 5 (9−aminopyronin), whose solutions exhibit a remarkable increase in fluorescence intensity together with a shift toward more energetic wavelengths. Other 9-aminopyronins 6a, 6b, 7a, and 7b were obtained from methanolic solutions of 4 with putrescine and cadaverine, demonstrating the potential of this new xanthene entity to react with primary amines.     

柱后加碱脉冲积分安培检测-离子色谱法测定水产品中十种生物胺

建立了利用淋洗液自动发生梯度淋洗的离子交换色谱法同时测定水产品中酪胺、5-羟色胺、腐胺、尸胺、组胺、庚二胺、苯乙胺、亚精胺、精胺、色胺等10种生物胺的方法。样品经处理后用Ionpac CS17分离柱和Ionpac CG17型保护柱分离,以EG40自动淋洗液发生器生成的5.0～55 mmol/L的MSA为淋洗液梯度洗脱,脉冲积分安培检测器检测。对梯度进行优化,10种生物胺都能基线分离,并且浓度和峰面积在一定范围内呈良好的线性关系。检出限在0.04 mg/kg以下,回收率在91.2%～102.5%之间,样品的RSD(n=6)小于5%。方法可用于水产品的检测。     

Fourier Transform Infrared (FTIR) Spectroscopic Analyses of Microbiological Samples and Biogenic Selenium Nanoparticles of Microbial Origin: Sample Preparation Effects

To demonstrate the importance of sample preparation used in Fourier transform infrared (FTIR) spectroscopy of microbiological materials, bacterial biomass samples with and without grinding and after different drying periods (1.5–23 h at 45 °C), as well as biogenic selenium nanoparticles (SeNPs; without washing and after one to three washing steps) were comparatively studied by transmission FTIR spectroscopy. For preparing bacterial biomass samples, Azospirillum brasilense Sp7 and A. baldaniorum Sp245 (earlier known as A. brasilense Sp245) were used. The SeNPs were obtained using A. brasilense Sp7 incubated with selenite. Grinding of the biomass samples was shown to result in slight downshifting of the bands related to cellular poly-3-hydroxybutyrate (PHB) present in the samples in small amounts (under ~10%), reflecting its partial crystallisation. Drying for 23 h was shown to give more reproducible FTIR spectra of bacterial samples. SeNPs were shown to contain capping layers of proteins, polysaccharides and lipids. The as-prepared SeNPs contained significant amounts of carboxylated components in their bioorganic capping, which appeared to be weakly bound and were largely removed after washing. Spectroscopic characteristics and changes induced by various sample preparation steps are discussed with regard to optimising sample treatment procedures for FTIR spectroscopic analyses of microbiological specimens.     

Separation of food-related biogenic amines by ion-interaction reversed-phase high performance liquid chromatography. Tyramine,histamine, 2-phenylethylamine,tryptamine and precursor aminoacids. Application to red wine

Summary Methods for the separation of food-related biogenic amines (histamine, tyramine, 2-phenylethylamine and tryptamine) have been developed based on ion-interaction reversed-phase liquid chromatography.Two different interaction reagents have been comparatively used, namely octylamine ortho-phosphate (at wave-lengths of 230, 254 and 280 nm) and octylamine salicylate (at a wavelength of 254 nm). The different elution sequence orders shown by the investigated amines for the two reagents are discussed and compared.The detection limits obtained were 20 ppb for tryptamine ( =280 nm), 500 ppb for 2-phenylethylamine (=254 nm), 400 ppb for tyramine (=230 or 280 nm) and 900 ppb for histamine (=230 nm).The method was applied to the analysis of a five years old Italian red wine, in which 2-phenylethylamine (at a concentration of 72±3 ppm) and tryptamine (at a concentration of 4.0±0.3 ppm) were found to be present.     

The reaction of Tanshinones with Amines

The reaction of cryptotanshinone and tanshinone IIA with several biogenic amine metabolites involved in the pathogenic pathways of HE were investigated and eight 1,2,3,4-tetrahydrophenanthrene derivatives,2-6 and 8-10,were obtained.The probable mechanism on reaction was discussed.     

Solid Polymer Substrates and Coated Fibers Containing 2,4,6‐Trinitrobenzene Motifs as Smart Labels for the Visual Detection of Biogenic Amine Vapors

Attempts to polymerize trinitrobenzene derivatives (TNB) have been fruitless so far. Accordingly, polymers containing TNB have not been exploited in spite of their envisaged potential applications. Here, we describe two ways for preparing polymers with TNB moieties thus overcoming the previously reported polymerization impairments. We also report on the exploitation of the materials, both obtained as tractable transparent films and coated fibers, as smart labels for the visual detection of amine vapors. More precisely, amines in the atmosphere surrounding the sensory materials diffuse into them reacting with the TNB motifs forming highly colored Meisenheimer complexes, giving rise to development of color and to the naked eye sensing phenomenon. This is the case of highly volatile amines, such as trimethylamine, produced in food spoilage, specifically in the deterioration of fish or meat, for which the color development of the smart labels can be used as a visual test for food freshness.     

Analytical approach to determine biogenic amines in urine using microextraction in packed syringe and liquid chromatography coupled to electrochemical detection

The goal of this work was to develop and validate an analytical method for the detection and quantification of the biogenic amines serotonin (5‐HT), dopamine (DA) and norepinephrine (NE), using microextraction in packed syringe (MEPS) and liquid chromatography coupled to electrochemical detection (HPLC‐ED) in urine. The method was validated according to internationally accepted guidelines from the Food and Drug Administration. Linearity was established between 50 and 1000 ng/mL for 5‐HT and between 5 and 1000 ng/mL for DA and NE, with determination coefficients (R²) >0.99 for all compounds. The limits of quantification and detection were respectively 50 and 20 ng/mL for 5‐HT, and 5 and 2 ng/mL for DA and NE. Within‐ and between‐run precision ranged from 0.84 to 9.41%, while accuracy ranged from 0.79 to 12.76% for all compounds. The intermediate precision and accuracy were 1.50–8.36 and 0.54–13.51%, respectively. The method was found suitable for clinical routine analysis of the studied compounds, using a sample volume of 0.5 mL. This is the first study employing a commercially available MEPS column for the simultaneous detection and quantification of 5‐HT, DA and NE in urine by coulometric detection. Copyright © 2012 John Wiley & Sons, Ltd.     

Sensitive profiling of biogenic amines in human urine by capillary electrophoresis with field amplified sample injection

In order to monitor biogenic amines in human urine, a method based on field‐amplified sample injection combined with capillary electrophoresis and direct UV absorption detection was developed. Dopamine, tyramine, tryptamine, serotonin and epinephrine were effectively separated and identified in human urine samples, and detection limits were 0.072, 0.010, 0.027, 0.010 and 0.120 µmol/L, respectively. Detection limits comparable to laser‐induced fluorescence detection or solid phase extraction combined with capillary electrophoresis were achieved. Parameters affecting electrophoretic system detection sensitivity were investigated. Optimal separation conditions were obtained using as background electrolyte a pH 6.5 mixture of 2‐(morpholino)ethanesulfonic acid 20 mmol/L and 30 mmol/L phosphate buffer, containing 0.05% hydroxypropylcellulose and 10% v/v methanol. Injections of the sample solution were performed by applying a voltage of 12 kV for 50 s. Recovery and accuracy ranged between 89.4 and 94.9%, and 89 and 112%, respectively. The method was successfully applied on actual urine samples (from a healthy volunteer): target bioamine content was consistent with endogenous levels reported in the literature. The proposed method is simple, fast and inexpensive and can be conveniently employed in work‐related stress studies. The affordability and noninvasive sampling of the method allow epidemiological studies on large number of exposed persons to be performed. Copyright © 2013 John Wiley & Sons, Ltd.     

Biogenic volatile organic compounds (BVOC) in ambient air over Hong Kong: analytical methodology and field measurement

In this paper, an analytical method using a simple semi-manual cryo-trap technique coupled to gas chromatograph with flame ionisation detector (GC-FID) was developed for the determination of biogenic volatile organic compounds (BVOC) in ambient air. Five common BVOC species have been tested, including isoprene and 4 monoterpenes, i.e. α-pinene, β-pinene, 3-carene (Δ) and limonene. The detection limits were estimated to be about 20 ppt for isoprene and 10 ppt for monoterpenes, with sample injection volume of 50 mL. Based on vegetation types, field measurement work was conducted over urban and rural sites of Hong Kong during summer and winter of 2007. Canister sampling technique was applied in the field measurement. Isoprene contents in rural ambient air were found to be in the range of 60～1560 ppt in winter and 260～3270 ppt in summer, respectively. However, in the measurement of monoterpenes, due to their extremely low concentration in the air samples, only β-pinene and limonene were detected by the developed analytical method.